An Italian Windows site called "Windowsette" has published some purported secret Microsoft documents outlining some design and strategy plans for Windows 8. The Microsoft Kitchen blog has provided some analysis of the documents. The documents appear genuine, and there's lots of interesting information there.

Just voted your comment up because that is what I would like very much: to have some kind of app store of repository for Windows users, and an option to allow 3rd party software installations. Indeed, it would allow power users to have fun, and normal users would be better protected. Maybe even multiple app stores / app sources / repos would be possible, e.g. sourceforge as a repo.